"Pheripheral Mechanisms of Hearing" is a proposal to establish the relationship between the vibrations of the basilar membrane of the mammalian inner ear and their neural correlates, the trains of action potentials that travel along the axons of the cochlear nerve. Thus, this proposal seeks to specify the framework upon which cochlear transduction (the conversion of mechanical signals into neural, electrical all-or-none events) takes place. The general strategy consists of parallel measurements using identical stimuli, of the vibrational response of the basilar membrane and of the electrical activity of single cochlear fibers in the chinchilla. The basilar membrane vibration will be measured by means of an application of the Mossbauer effect that permits detection of very low velocity (e.g., 0.03 mm/sec.) Results of the proposed investigation will be of value in specifying the framework of normal mechanical-to-neural transduction in the human ear (which is not too dissimilar from its chinchilla counterpart). Results will be also of value in specifying possible mechanical aspects of pathology in human deafness.